Means for electroplating tubes internally and externally



y 1930- v. L. .SODERBERG Er AL 1,759,171

MEANS FOR ELECTROPLATING TUBES INTERNALLY AND'EXTERNALLY Filed May 12, 1927 f fi 7 W Z QF r L Patented May 20, 1930 'NtTED Zfi'ii'ATES VICTOR Ia sons-arena, or nmaorr,

PATENT oFncE MICHIGAN, AND C. R OY GLEAEON, OF CHICAQO,

ILLINOIS MEA.N8 FOR EIIEGTRQPLATING TUBES INTERNALLY AND EXTEBNALLY Application filed May 12,

make it feasible simultaneously to plate both the inside and the outside of the tube or member having parts that are more or less tubular, in a simple manner; especially in the case of chromium plating.

The various features of novelty whereby our invention is characterized will hereinafter be pointed out with particularity in the claims; but, for a full understanding of our invention and of its objects and advantages. reference may be had to the following detailed description taken in connection with the accompanying drawing, wherein:

Figure 1 is a view partly in elevation and partly in section of a tube to be electroplated internally and externally and holding means therefor, the electroplating apparatus being indicated more or less diagrammatically; and Fig. 2 is a section taken on line 22 of Fig. 1.

In the drawings we have illustrated our invention as applied to the electroplating internally and externally of a simple tube. and the detailed description will be confined to this example; as it will be understood that only the details of the combined anode and holder need be changed to adapt it to plating externall or internally, globe valves, Ts, pet cocks an plumbing fixtures and laboratory fixtures in general.

Referring to the drawing, A represents the tube to be electroplated with chromium or other metal. This tube is first placed in a suitable holder which constitutes one of the anodes. In the arrangement shown, the hold er consistsof a rod 1 of metal, preferably iron- Arranged on this rod are clamping heads in the form of cups having, their open sides directed toward each other. 'Each'cup conveniently consists of a.. nietal sleeve 2 closed at one end with a block 3 of insulating material notafieggedby the electrolyte to be employed eitiiiiling into a counterbore in the 1927. Serial 170. 180,771.

sleeve; the rod being coaxial with thecups and passin g through the bottoms of the latter.

Each of the sleeve members has one or more,

preferably a plurality of holes 4 extending through the walltbercof and is countersunk at the end forming the mouth of the cup, as indicated at 5, to provide a seat to receive one end of the work and thus bring the work accurately coaxial with the rod 1. Both ends of the rod are screwthreaded, the threads extending for a considerable distance along at least one end of the rod, preferably the upper end. Nuts 6 and 7 are placed on the rod outwardly of the insulating blocks. When one of the nuts, say the nut 7, is removed, the

corresponding cup may be slipped from the rod, permitting the application of a tube. After the tube has been placed on the rod, the cup is replaced and the nut screwed on, thereby causing the tube to be firmly clamped between the two cups. By providing screwthreads throughout a considerable length of the rod, the device is adapted to receive tubes of variouslengths within comparatively wide limits.

For thepurpose of plating the tube internally, the tube must be acting as the cathode and the rod as the anode. the sleeves and the rod should be provided with or constitute terminals. serving as part of a holder for the work and In addition to 'l'herefore one of r as an anode, the 'rod-mayalso serve as the -means for suspending the work in the plating bath. l'n'the drawing we have diagrammatically illustrated so much of the plating apparatus as is necessary to explain the use of our invention, including a fragment of the tank 13, anode bus bars C, C, a cathode bus bar D, and anodes c, 0, depending from the bus bars G, O; The anodes c, 0 are plates or M knurled nuts 9 and 10 adapted to engage opposite sides of that arm of the bracket through which the rod passes, so as to secure the rod to the bracket and complete a good electrical connection between the rod and one of the anode bus bars. The upper sleeve 2 of the holder has a wire 11 fastened thereto. This wire'is' adapted-to be wrap ed around the cathode bus bar, placing the s eeve and thereforethe work in electrically conductive relation to the cathode bus bar.

The cathode bus bar lies between the other two has bars, so that the work, when suspended in the plating bath, will lie within and at the axis of the cylindrical shell formed by the two anodes c, a. In some cases the anodes c, 0 need not be curved but may be flator of any other shape.

Assuming that the parts have been assembled as shown in the drawing, and that the tank contains the requisite electrolyte, preferably one adapted for the deposition of chromium, and that the proper current is flowing, it will be seen that there will be an even deposition of metal around the interior of the work because of the centralized anode. Similarly, since the work lies between the two outer anodes, there will be uniform distribution of the metal deposited on the exterior of the work.

The openings in the sides of the cups between which the work is held permit the electrolyte to circulate, so that the strength of the electrolyte producing the internal plating .will not become unduly diminished. Furthermore, as ases are evolved within the tube during the p ating process, they are permitted to escape through the holes in the upper cu instead of building up a pressure.

[he present invention is particularly useful for electroplating with chromium, but it is not limited to this particular field.

While we have illustrated and described with particularity only a single preferred form of our invention, we do not desire to be limited to the exact structural details thus illustrated and described; but intend to cover all forms and arrangements which come within the definitions of our invention constituting the appended claims.

We claim:

1. A combined anode and holder for a tube to be electroplated,comprising arod,a clamping head in the form of an inverted perforated cup on the upper end of the rod, and a second clamping head on the lower end of the rod, the heads being adj ustablerelatively tpfleach other and one of them beingdetacha e.

2. A combined anode and holder for a tube to be electroplated, comprisin a rod, a

clamping head on the upper en of the rod,

and a second clamping head on the rod below the other head, one of the heads being detachable, the upper head having a part of conducting material insulatedfrom said rod and adapted to engage a tube arran ed in the holder, means for suspending sald rod in electrically conductive relation to a bus bar, and means for connecting said part of conducting material to a second bus bar.

, 3. A combined anode and holder for a tube to be electroplated, comprising a rod, 9. clampin headin the form of an inverted cup on the upper end of the rod, and a second clamping head in the form of an upright cup on the rod below the upper head, one of the heads being detachable, therim portion of said cu s being the contact-making art with the en s of a tube clamped between t em, and both cups being perforated.

4. Inun electroplating apparatus, a tank provided with bus bars a rod, means for suspending the rod in electrically conductive relation with one of said bus-bars, clamping heads on said rod to hold a piece of work, one of saidheads having a part of conducting material adapted to contact with the work, and means for electrically connecting said part to another of the bus bars.

5. A combined holder and anode comprismg a rod, two clamping heads slidable on the rod, shoulders on the rod to limit the vrelative movements of the heads away from each other, one of said shoulders being a nut screwed on the rod, said heads being in the form of cups with their mouths directed toward each other, and each cup comprising a erforated metal sleeve and a bottom of insu ating material through which the rod passes.

6. A combined holder and anode, comprismga' rod, two clamping heads on the rod, each head consisting of a metal sleeve counter'bored at each end and a block of insulating material fitting into each 'of the coun terbores and forming with each sleeve 9. cup, the cups having their mouths directed toward each other, and shoulders, at least one of which is a nut, on the rod to limit the move ments of the cups away from each other.

In testimony whereof, we sign this specification.

VICTOR L.- SODERBERG. C. ROY GLEASON. 

